You are right, the instance should be shutdown or the device be unmounted, before 'revert' or removing the old device. That should be enough to avoid corruption. I think the device naming is not a problem if you use the same volume (at least the disk UUID will be the same).
On Mon, Apr 11, 2016 at 2:39 PM, Duncan Thomas <duncan.tho...@gmail.com> wrote: > You can't just change the contents of a volume under the instance though - > at the very least you need to do an unmount in the instance, and a detach > is preferable, otherwise you've got data corruption issues. > > At that point, the device naming problems are identical. > > On 11 April 2016 at 20:22, Erlon Cruz <sombra...@gmail.com> wrote: > >> The actual user workflow is: >> >> 1 - User creates a volume(s) >> 2 - User attach volume to instance >> 3 - User creates a snapshot >> 4 - Something happens causing the need of a revert >> 5 - User creates a volume(s) from the snapshot(s) >> 6 - User detach old volumes >> 7 - User attach new volumes (and pray so they get the same id) - Nova, >> should have the ability to honor supplied device names (vdc, vdd, etc), >> which not always happen[1]. But, does the volume keep the same UUID in the >> system? Several application use that to boot. >> >> The suggested workflow would be simpler for a user POV: >> >> 1 - User creates a volume(s) >> 2 - User attach volume to instance >> 3 - User creates a snapshot >> 4 - Something happens causing the need of a revert >> 5 - User revert snapshot(s) >> >> >> [1] https://goo.gl/Kusfne >> >> On Fri, Apr 8, 2016 at 5:07 AM, Ivan Kolodyazhny <e...@e0ne.info> wrote: >> >>> Hi Chenzongliang, >>> >>> I still don't understand what is difference between proposed feature and >>> 'restore volume from snapshot'? Could you please explain it? >>> >>> Regards, >>> Ivan Kolodyazhny, >>> http://blog.e0ne.info/ >>> >>> On Thu, Apr 7, 2016 at 12:00 PM, Chenzongliang <chenzongli...@huawei.com >>> > wrote: >>> >>>> Dear Cruz: >>>> >>>> >>>> >>>> Thanks for you kind support, I will review the previous spec >>>> according to the following links. May be more user scenario we should >>>> considered,such as backup,create volume from snapshot,consistency group and >>>> etc,we will spend some time to gather >>>> >>>> the user's scenarios and determin what to do next step. >>>> >>>> >>>> >>>> Sincerely, >>>> >>>> zongliang chen >>>> >>>> >>>> >>>> *发件人:* Erlon Cruz [mailto:sombra...@gmail.com] >>>> *发送时间:* 2016年4月5日 2:50 >>>> *收件人:* OpenStack Development Mailing List (not for usage questions) >>>> *抄送:* Zhangli (ISSP); Shenhong (C) >>>> *主题:* Re: [openstack-dev] [Cinder] About snapshot Rollback? >>>> >>>> >>>> >>>> Hi Chen, >>>> >>>> >>>> >>>> Not sure if I got you right but I brought this topic in >>>> #openstack-cinder some days ago. The idea is to be able to rollback a >>>> snapshot in Cinder. Today what is possible to do is to create a volume from >>>> a snapshot. From the user point of view, this is not ideal, as there are >>>> several cases, if not the majority of, that the purpose of the snapshot is >>>> to revert to a desired state, and not keep the original volume. For some >>>> backends, keeping the original volume means space consumption. This space >>>> problem becomes bold when we think about consistency groups. For >>>> consistency groups, some backends might have to copy an entire filesystem >>>> for each snapshot, consuming space and time. So, I think it would be >>>> desired to have the ability to revert snapshots. >>>> >>>> >>>> >>>> I know there have been efforts in the past[1] to implement that, but >>>> for some reason the work was stopped. If you want to retake the effort >>>> please create a spec[2] sol everybody can provide feedback. >>>> >>>> >>>> >>>> Erlon >>>> >>>> >>>> >>>> >>>> >>>> [1] >>>> https://blueprints.launchpad.net/cinder/+spec/cinder-volume-rollback-snapshot >>>> >>>> [2] https://github.com/openstack/cinder-specs >>>> >>>> >>>> >>>> On Thu, Mar 24, 2016 at 6:09 AM, Chenzongliang < >>>> chenzongli...@huawei.com> wrote: >>>> >>>> Hi all: >>>> >>>> We are condering add a fucntion rollback_snapshot when we use >>>> backup. In the end user's scenario. If a vm fails, we hope that we can use >>>> snapshot to to recovery the volume's data. >>>> >>>> Beacuse it can quickly recovery our vm. But if we use the remote >>>> data to recovery. We will spend more time. >>>> >>>> But i'm not sure if the data was recoveried from the backend. >>>> whether the host need to rescan the volumes? At the same time. If a volume >>>> have been extended, whether it can be roolback? >>>> >>>> >>>> >>>> I want to know whether the topic have been discussed or have other >>>> recommendations to us? >>>> >>>> >>>> >>>> Thanks >>>> >>>> >>>> >>>> __________________________________________________________________________ >>>> OpenStack Development Mailing List (not for usage questions) >>>> Unsubscribe: >>>> openstack-dev-requ...@lists.openstack.org?subject:unsubscribe >>>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev >>>> >>>> >>>> >>>> >>>> __________________________________________________________________________ >>>> OpenStack Development Mailing List (not for usage questions) >>>> Unsubscribe: >>>> openstack-dev-requ...@lists.openstack.org?subject:unsubscribe >>>> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev >>>> >>>> >>> >> >> __________________________________________________________________________ >> OpenStack Development Mailing List (not for usage questions) >> Unsubscribe: >> openstack-dev-requ...@lists.openstack.org?subject:unsubscribe >> http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev >> >> > > > -- > -- > Duncan Thomas > > __________________________________________________________________________ > OpenStack Development Mailing List (not for usage questions) > Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe > http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev > >
__________________________________________________________________________ OpenStack Development Mailing List (not for usage questions) Unsubscribe: openstack-dev-requ...@lists.openstack.org?subject:unsubscribe http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev
